Crazy, today I was just wondering if they're going to update the 400 DO lens, and then I see this post about the patent for it. It's a pretty old lens and could use an update. I believe the IS on the old lens only offers 2 stops of image stabilization, so it would be great for them to upgrade it to at least 4 stops of image stabilization. Also if they can make it even lighter, and have better contrast wide open, then I think they'll have a winner in their hands. I just hope it's not as pricey as the recent batch of Canon's Super Telephotos

I think if Canon could find a way to keep their lens purchase price at a more reasonable level and can correct the lack of contrast and lower sharpness that DO tech causes, then I think Canon would have a winner on their hands.

A 400m f2.8 DO that's 1/3 of the weight but carries the same IQ that the L version offers can only be good.

With all these DO patents, We can expect an major unveiling of an entire new Canon DO line-up sometime in the future. Its would be a nice to have an more affordable versions of the larger longer lenses 300mms and up.

With all these DO patents, We can expect an major unveiling of an entire new Canon DO line-up sometime in the future. Its would be a nice to have an more affordable versions of the larger longer lenses 300mms and up.

+1 on that. I wonder if 600mm f/4 DO would represent an alternative to the 500mm f/4, for wildlife -- in terms of weight and hand-holdability implied by the shorter physical length. ... and what would the price be, and how would Canon position this one along side the today's 600mm. And would it play well with a 1.4x....

All that aside, a shorter/lighter/cheeper 600mm f/4 would be wonderful, and give wildlife folks a new option.